If you're ever being attacked by a lion, find a herd of elephants as quickly as you can...but if they're not led by an older female, you're dead meat. It's more remarkable evidence of elephants' ability to learn and cooperate.

There really does appear to be some truth to the old adage that an elephant never forgets, but it can take an elephant an awful long time to learn crucial information. Researchers from the UK's University of Sussex found this out in recent experiments that simulated imminent lion attacks on various elephant herds in their natural African environment. They played recordings of first male and then female lion roars, and they then charted the reaction when played for thirty-nine different groups of female elephants.

When the herds were led by particularly old females - also known as matriarchs - the groups responded exactly as they should to the male lion roars. The elephants first listened carefully to determine the precise nature of the roar, and then they bunched together in a defensive cluster. Some of the groups even started moving toward the sound of the roar to taken on what they assumed was a lone male lion.

The fact that they only responded to the male roar is significant. Lionesses will almost never attack elephants unless they're in a large group, but a single male lion can successfully take down a young elephant if it's all alone. Researcher Karen McComb explains why the elder-led groups responded appropriately while the groups led by younger females failed to take the threat seriously:

"Younger matriarchs didn't seem as bothered by male lions as they should have been. We think its because they hadn't had sufficient exposure to that threat; lions don't [attack elephants] that often."

She also noted that we still don't know quite how the matriarchs pull off two of their most impressive feats. One, they're able to tell the difference between male and female lions by their roar, when even we have trouble picking up on the incredibly subtle differences between them. And two, we're not sure how the matriarchs get all the other elephants organized without any loud vocal cues - somehow, it's all in the elephant's posture and possibly some soft vocalizations.

However they're doing it, it's just more amazing proof of just how intelligent and strategic elephants really are, and how dependent they are on a simple social structure that relies on the wisdom of elders.